SPRINGFIELD, Ill. (AP) -- A major teachers union argued Tuesday that tenured teachers are almost never fired in Illinois because people who can't perform are usually forced out before a formal termination hearing is needed.

"There is a `weeding out' system that kicks in well before a hearing takes place, and it has served the students and the taxpayers of the state well," said Ken Swanson, president of the Illinois Education Association.

The comments were in response to a six-month investigation by the Small Newspaper Group, which found that teachers rarely lose their jobs under an accountability law that was passed in the mid-1980s.

The investigation showed that only 7 percent of school systems have even attempted to fire a tenured teacher. On average, two of the state's 95,000 tenured teachers are fired for poor job performance each year. Five more are dismissed for misconduct.

The IEA said teachers must survive a four-year probationary position before they obtain tenure and the job protections that go with it. Even if tenured teachers are rarely fired, they can be encouraged to leave.

"The news reports don't show how many teachers voluntarily left districts because they weren't performing, or how many were not renewed during their probationary years," Swanson said.